Share

Science fiction has shown us a thousand versions of life in space, but Gravity is the rare film that attempts to capture the reality. Alfonso Cuarón's space odyssey is like walking into one of those glorious full-color NASA photographs (which we can't link to right now — thanks, Congress!), accompanied by the best-looking astronauts in history. Aside from the presence of Sandra Bullock and George Clooney, everything in the film feels immediately, startlingly real. Which of course made us wonder: What is real, and where does artistic license come into play? Astrophysicist Neil DeGrasse Tyson attempted to answer some of those questions on Twitter yesterday, and for a guy working in 140-character sound bites, he did a good job. Still, we thought it might be even more grounded to fact-check the film with someone who had actually, you know, been to space.

Former U.S. astronaut Scott Parazynski has done seven space walks, including the time he spent seven hours dangling from a robotic arm at the International Space Station, repairing a solar panel array that could have electrocuted him at any time. He had to watch that very solar panel get slashed to bits during Gravity, but aside from that moment, Parazynski loved the film. Vulture had a long, spoiler-filled conversation with the astronaut about space debris, jet packs, tears in space, and Sandra Bullock's underwear.

So you enjoyed the film? No post-traumatic stress?I got a little homesick for being in space, actually! The opening sequence, on the EVA, when they're flying over a beautiful hurricane on the planet — it was kind of jaw-dropping, but even in 3-D, it doesn't have the full impact that a real Earth pass would have. But it's about as good as you can get. It is that kind of powerful sense of being "out there." It's the greatest job in the universe, so there are times when you've got your head down and you're working on a computer board, and you look up and there's a hurricane, or there are the Himalayas, and you really realize how fortunate you are. So I really enjoyed that.

Sandra Bullock says she likes the silence of space; how silent is it, really?When you're in your spacesuit, actually, there's a very comforting hum. You're always hearing the purr of your fan, which is your lifeline, it's what circulates your oxygen through your suit. You're hearing the crackle of the radio. It's just kind of a reassurance that you're still connected. When your spacesuit goes completely silent, that's a really, really bad day. So we don't like it to be completely silent. But there is a powerful beauty in being up there; I just wouldn't describe it as silent.

How early in the film did you see something and go, "Wait, that would never happen"?One thing that immediately set alarms off was having three people out on an EVA with only one person doing the work. Poor Sandra was doing all the work, and those other two guys were just kind of playing around; one of them is on the equivalent of a jungle gym down in the Shuttle’s payload bay, and Clooney is zipping around in a turbo-charged MMU. The MMU is the Manned Maneuvering Unit that we used to fly in the Shuttle program a long time ago. You would never, ever fly like George Clooney's character did. So you know, he's flying in close proximity to the Hubble Space Telescope. If you were to do that, you would plume the solar arrays, bend them and make them probably inoperative. So it was just all wrong. [Laughs.] The MMU is really neat technology, but it moved much more slowly than that for a lot of reasons. When you're flying in Earth orbit, you're actually traveling at 17,500 miles an hour, and so there are orbital mechanics effects that you have relative to Earth, as well as to the spacecraft that you're flying around. And so it's actually quite a bit more involved than would be suggested by the way George was flying around.

You said the existing technology wouldn't be able to travel the distance between space stations. How far apart are the Hubble and the International Space Station, for example?That was the other kind of glaring thing. The fact is, the Hubble is in its particular orbit, the ISS is in its particular orbit, and then the Chinese space station is in its particular orbit. Without getting too involved in orbital mechanics or the orbital insertion planes of these different satellite systems, they aren't close to one another, ever. So Hubble is in an orbit fairly close to the equator … kind of around the belly band of the earth, but at a very high altitude, around 400 miles above the earth. And then the ISS is at a very high inclination, so it sees from basically the latitude of Kazakhstan to an equivalent latitude in the southern hemisphere … so a much greater swath of Earth. The bottom line is that they’re in very different places, traveling at different altitudes and orbits of the earth, so they're not at fixed distances to one another. They're basically speeding bullets relative to one another. Their orbits cross at varying times throughout the day, and it would be physically impossible to get from one place to the other.

So in reality, if you were out at the Hubble —You're out of luck. [Laughs.]

When George Clooney is zipping around the spacecraft, they say he's testing a new jet-pack technology. Do you think he would have been untethered like that?No. Well, if you're flying the MMU to go grapple a satellite, sure; in fact, they did this three or four times early in the Shuttle program, and they did take sorties out to a few hundred feet to demonstrate the flying capabilities of it. In one case, they actually captured a satellite and brought it back to the orbiter. But fairly short distances. Every other time, we're always tethered to the spacecraft. And it's a steel metal braid cable on a retractable reel, and so as you pay out cable, it reels out, and as you get closer to the spacecraft, it reels back in. So we're always tethered to the mothership, whatever that happens to be; if it's the robotic arm, or the Shuttle or the International Space Station.

What did you think of the way the astronauts moved in space?They kind of made it look like moving up on a pommel horse, taking these huge, lunging grabs for things. And actually, if you look at skilled spacewalkers, it's very graceful. It's kind of beautiful. If you are really a master in the suit, you can work through the center mass of the suit, and it looks almost effortless. It takes quite a bit of effort, actually, but you're very smoothly controlling your inertia, and you're not only moving in space, but you're changing your body attitude just the right amount. So you're not overreacting or overcorrecting all the time. What they did in the movie is they kind of lunged and grabbed and really wrestled the suit, and we call that being a bull in a china shop. That's what we train the new guys to try and avoid, instead to be very smooth with their inputs, to just use the right amount of force. Say if you're going to pitch your feet up, so you're going to want to bring your feet forward. That's going to take a certain amount of force. But you're also going to have to damp that out once you get them to where they need to be. So once you've reoriented your body where you want it to be, you have to impart another force to counteract that, to stabilize them in the new body orientation you want to be in. So you want to do all this in a very controlled, deliberate way. When you're moving a spacesuit that is fully loaded with tools, and your own personal bodyweight, and the things you have in your backpack, it's about 630 pounds' worth of mass. It gets very tiring very quickly if you're not smooth and deliberate about it.

Let's talk a little about the plausibility of Sandra Bullock's character. She was supposed to be pretty inexperienced; she says she trained for six months, was on her first mission, and never successfully landed a flight simulator. Would someone with that level of experience and training be sent on the mission she's sent on?No, but it worked for the story, and she looked really good. [Laughs.] So, she called herself a mission specialist, but she would actually be what we would refer to as a "payload specialist": someone who was brought on to a flight late in the flow with a very special skill set, to do a particular task or experiment. What I would say, though, is that to become a spacewalker, it's at least a couple years of training just to have the basic skill set to go do that. So we've never sent a payload specialist out to do a space walk. The folks that did space walks in the shuttle program, like myself, were mission specialists, so we were professional astronauts and did a number of different roles in the program, including science. But payload specialists came on for a particular experiment, typically, but they never did space walks. To go out and do space walking, you need to learn everything about the spacesuit systems, how to function in all the different EVA systems — it's a tremendous amount of training. The other thing is that a payload specialist wouldn't be expected to land even a simulator. They would come onboard just to do a particular task, and they would fly one time, and that would be it.

One of the first things we hear her say is that she feels nauseous. Is that normal for someone on their first flight?Yes, about 40 percent of first-time fliers experience some degree of Space Adaptation Syndrome, what we call SAS or space motion sickness. We have good medicines for it onboard now, but typically it's limited to the first couple days of flight. And we never do space walks until, typically, the fourth day of flight, because of that. So it would be very uncommon for a space walker to have motion sickness during an EVA. In fact, it would be scary if you were to lose your cookies in the middle of a space walk. You could actually be blinded, among other things. Not to get too graphic, but surface tension predominates up there, so you could have a visor cover full of stuff you didn't want on your spacesuit, and it would prevent you from getting back into your airlock.

I was actually wondering about that — if you vomit, does it just float there?That's actually what would happen. It would actually stick then, to the visor, because surface tension is the strongest force up there and yeah, it would be impossible for you to clear it out of the way, really … There was one Apollo mission, Apollo 9, where one of spacewalkers ended up having pretty severe motion sickness, and it delayed the space walk.

What's your experience with space debris? If you're out on a space walk, what are you seeing around you?Well, first of all, if you see it, it's too late. That was quite implausible, to me, first off, the chain of events that would take down the world's telecommunications. Things don't quite move in that pattern. But that notwithstanding, if there were a cloud of Micro-Meteoroid Orbital Debris, what we call MMOD, it would be coming at tens of thousands of miles an hour. I don't know if you've ever looked at a bullet coming straight at you. Hopefully not, but if you had, you wouldn't appreciate it for very long. And these would be a much tinier, swarmlike pattern of debris coming at perhaps twenty times the speed of sound. And you wouldn't see it at all; it would just rip through everything in its path. So it's kind of a spacewalker's doomsday scenario.

The astronaut who was hit by debris had a giant gaping hole through his visor and face. Is that actually what would happen, were an astronaut hit?Honestly, I think that would be quite improbable as well. The kinetic energy that orbital debris has, it's just a phenomenal amount of energy that would convert into heat. As soon as it contacted the 100-percent oxygen environment inside the suit, I think there would be a combustion event. You would have basically a flash fire, and everything inside the suit would be quickly incinerated. So kind of a grisly way to go.

But this is a scenario that's never happened, right?Never happened. But we have taken lots of orbital debris. In fact, every shuttle flight that we flew, there would be dings on the windows, as well as to the Shuttle’s tiles. I actually have experience seeing debris damage when floating by a radiator panel. I was at the very tip of the space station; it was a much larger piece of debris, but it went all the way through the panel, and it looked like a bullet had been shot through it. There were curved metal ridges that showed the spiral pattern. It was probably just a washer from a spent booster or something that ended up crossing the station's path. These things have incredible energy. Even a fleck of paint traveling at those kinds of speeds could wreak havoc for a spacewalker.

We see quite a few worst-case scenarios in the film. George Clooney ends up untethering himself from his crewmate and literally floating away into space. Is dealing with that scenario part of your training? Or does that not even come up?Actually, I really couldn't understand the tension there. Sandra has her leg caught in some parachute rigging, and she's holding on to George by his hand. I think all he would have needed to have done would be to crawl up on her, and basically rope-climb up toward the space station. Or just lightly pull and he could have flown himself up to the space station. There would be no continuing motive force to continue to pull him away. So that physically didn't work for me.

So when George he let go of her hand, if it was in real space, he wouldn't have been pulled away.He would have just floated there.

That would have been somewhat less dramatic.Yes. [Laughs.] But getting back to your initial question, when Ed White did America's very first space walk [in 1965], there was a very real threat that he wouldn't be able to get back into his Gemini spacecraft. And so I think it was Jim McDevitt, who was the commander of the mission, who was actually briefed and trained that if there was any difficulty with getting Ed back in, he'd close the hatch and send him on his merry way. At that point, you have to salvage whatever you can of the mission. But we've never really had to face that threat directly since. We've known that we could get at least back into the airlock. In the shuttle program, we actually had the luxury of having a shuttle crew capable of undocking and potentially scooping us up. The other thing that's true is, 90 minutes after the major event, you would come back to the same point in the sky, more or less. So if you were to become detached from the shuttle or station, 90 minutes later, you could come back to the same point in the sky and you could grab back on, theoretically, if you had enough oxygen.

There's a terrifying moment where Sandra's character is spinning and she can't stop. What would you do in that situation?We had a device called SAFER; it's an acronym that stands for the Simplified Aid for EVA Rescue. So we would engage that system with a Nintendo-like hand controller, and fire some jet thrusters — it's basically a parachute, a mini-MMU. And that would stabilize our orientation, and then we would see where we are relative to the space station and fly ourselves back to safety.

The fire extinguisher-as-jet-pack thing: good idea or bad idea?Well, it doesn't work so well; actually Ed White — back to him — he had a little handgun like that, that allowed him to fire some jet thrusters, and the idea was to be able to zip around in space. It's very difficult to control the thruster through your center of mass; that’s why she was kind of bucking around in the sky, because she wasn't able to hold the thruster exactly opposite the direction she wanted to go. But the physical principle of what she was trying to do there is right on. It would be a tough flight, though.

What happens when you cry in space?Tears wouldn't float off of your eyes and face — they would pool in your eyes like a blob, like in the movie Flubber. Surface tension predominates. That said, the artistic license they took by having them float off Sandra's face was very cool.

What did you think of the scene where she crash-landed to Earth in the Chinese space station?It was dramatic, but improbable. You start to interact with the upper reaches of the atmosphere, what we call "entry interface," at 400,000 feet, so that's roughly 80 miles above the Earth’s surface. It appeared that the station was substantially above that in the scene, and it probably wouldn't have decayed from its orbit that quickly. That was quite dramatized there, when she's kind of holding onto this bucking bronco of the Chinese space station. It would probably take months or years, even if the station had been hit by lots of and lots of debris, to decay down to that altitude where atmospheric drag would take hold. And that's, of course, how the Skylab and all the Russian space stations were brought down: They fired their engines, lowered their altitude to the point where it could interact with the Earth's atmosphere, and they became fireballs prior to falling to earth.

Would a person in a capsule from the space station survive?Yeah, I think if the pod were to separate and get out of the debris field, I think you might. I was kind of having a nightmare during that scene: I can read Russian and speak Russian, but to be in a Chinese capsule and trying to press buttons, and which one is the undocking button? [Laughs.] Wow. That would be scary.

So are they basically the same setup? Would you be able to improvise and land a Chinese spacecraft?Well, I haven't really seen their capsule, but I do know that it's a very close cousin of the Russian Soyuz capsule. And so I'd imagine that they even had some technology-sharing between the countries as they were building their Shenzhou. It's reasonable to think that they probably have a pretty similar setup, but I really don't know.

The pod she ends up in, aren't they actually designed to land in water? She starts sinking pretty fast in the film.The Soyuz capsule, and I think the Shenzhou as well, is capable of landing in water. It's designed for landing on land, but there are water survival devices on them: inflatable rafts, things like that that would theoretically inflate on contact with water and prevent it from sinking. But it is kind of a worst-case scenario. And I think the filmmakers leveraged off of some real history, which is nice. Gus Grissom on the second American space flight, did exactly that. The hatch came open, the rough seas began to enter into the capsule, and the spacesuit itself isn’t that swimmable. Gus in real life and Sandra in the film had their helmets off. As soon as she got into the water, the water filled into her suit, and then she became negatively buoyant. So after she got out of the capsule she sunk to the bottom. It was kind of a nightmare. But I think in the real world, the Soyuz or the Chinese capsule would probably have inflatables that would stabilize it in the water, and you could get out at a more leisurely rate.

Let’s end with a critical question: Had Gravity turned into a love story, would George and Sandra have been able to consummate their relationship? What the Internet told me is that there has never been documented sex in space.[Laughs.] No one has ever spoken of it, no. Who knows what goes on aboard long-duration space missions on space stations, but certainly in the shuttle world, there would be no privacy for such intimacies. And certainly on one of the Soyuz capsules, they’re too tiny. But it's hard to say whether or not those kinds of things have happened on longer flights. A married couple flew aboard a shuttle at one point, but they were on different shifts, so it wasn't in the flight plan, so to speak.

Any other glaring things you want to mention?I really don't like picking on this movie, because I really loved it — but the fact that Sandra wasn't wearing either a liquid-cooled ventilation garment or a diaper under her spacesuit was an EVA faux pas. She came out in this form-hugging Lycra underwear, which I must say looked really good, but she wouldn't have been well postured to withstand the temperature extremes of minus 200 in the shade and up to plus 300 in the direct sunlight. And she wasn't even wearing socks, which I thought was interesting. Frostbite would be a real threat there.